Standard treatment for locally advanced gastric cancer currently involves surgery combined with chemotherapy administered both before and after the operation. However, post-surgery (adjuvant) chemotherapy often causes severe side effects, and it is unclear if all patients truly benefit from it. Recent research, such as the SPACE-FLOT study, suggests that patients who respond well to pre-surgery treatment might not actually benefit from further aggressive treatment after surgery; in these cases, additional therapy may only increase the risk of side effects without improving survival.
To address this, researchers are investigating circulating tumor DNA (ctDNA) testing, which detects microscopic traces of cancer (Molecular Residual Disease, or MRD) in the blood. The utility of ctDNA is supported by extensive research:
In Colorectal Cancer: The GALAXY study demonstrated that ctDNA status accurately predicts patient survival and identifies who benefits from chemotherapy. Furthermore, the DYNAMIC study showed that using ctDNA to guide treatment decisions significantly reduced the use of unnecessary chemotherapy without compromising patient survival.
In Gastric Cancer: Studies such as MENCA-GC, CRITICS, and PLAGAST have confirmed that post-surgery ctDNA is a strong predictor of patient prognosis. Additionally, the MRD-GATE study provided preliminary evidence that ctDNA-guided strategies can reduce unnecessary chemotherapy in the adjuvant setting.
Building on this evidence, this study applies ctDNA testing to the standard perioperative treatment model for gastric cancer. The primary objective is to determine if a ctDNA-guided strategy can identify patients who can safely forgo post-surgery chemotherapy, thereby reducing treatment toxicity and unnecessary usage, without sacrificing long-term survival outcomes.
Be able to provide a written informed consent form (ICF), and understand, agree to, and comply with the study requirements and assessment schedule.
Male or female aged 18 to 79 years.
Histologically confirmed gastric adenocarcinoma or adenocarcinoma of the gastroesophageal junction (GEJ), with clinical TNM staging (per the 8th edition of the AJCC/UICC Clinical TNM Staging for Gastric Cancer) as clinical Stage cIII to cIVa, and the primary gastric cancer lesion assessed to be amenable to curative resection.
ECOG PS ≤ 2, tolerable to surgical treatment, no surgical contraindications.
Subjects for whom investigators consider that there are obvious contraindications to (neo)adjuvant treatment or who cannot tolerate (neo)adjuvant treatment.
Females of childbearing potential who have not undergone surgical sterilization or do not use adequate contraceptive measures, pregnant or lactating females, and males who plan to impregnate their partners in the near term.
Any severe or uncontrolled systemic disease, including but not limited to uncontrolled hypertension, active bleeding, diabetes mellitus, and others.
Severe chronic or active infections that require systemic antibacterial, antifungal, or antiviral therapy, including but not limited to tuberculosis (TB), human immunodeficiency virus (HIV) infection, and others.